Constant magnitude control system



y 1931. P. R. DIJKSTERHUIS 1,804,325

CONSTANT MAGNITUDE CONTROL SYSTEM Filed Aug. 12. 1929 Fotentefi they i931 new: EB DLIKQS, 9F EINDHQVEN, E TETHERMEIDS, IGNQR T N. V.

IPEILHS GLQEILAIMENFABBIHEN, 0F no;vrst, News, 2. LIMITED LIA'EMTY 9F THE NET w GQNQTANT menrronn connect hpolicetion filed magnet 12, 1929, Seriol Ho. 3%;45'39, nntl in the Hetherieniie tictohcr SA; 3928,

The invention is concerned with a. device which ellows of keeping within narrow limits o temperature, e voitsge, a speed ore simiier rncgnitude.

According to the invention, for this purpose e rnoveole conductor whose momentary position depenols on the momentary value of the magnitude to be regulated and which is connected with to source of voltage, is orw rengeti between two stationery conductors winch ere errsngeol et some mutual distance from each other. These letter conductors ere connected with the i control grids of two thermionic tubes end with one of the electrooles of two condensers whose other electcodes ore connected with the above mentionecl source of voitege end with the cathot the seicl tuhes the anode circuits of these tuhes noting opposite senses on the velue of the megnitucle to he controlled.

Further ieetures oi the invention will eppeer from the following description in which niocle reelisetion oi? the invention is en- ;oieineol more fuliy with reference to the occompenying chewing,

the i enci 2 denote stationery hetween which is left e smell nerrow intervening specs is ,ointrer 3 ct measuring instru- "rich in the unfier consideration sup oc e o motes for indicating the eel to e or of eiectric furnace 5, which --ture it is desired to keep as constant 31 is eiectriceily connected with or 11.8 terminels of at source c oi high go whose other terminal is connected it one the electrodes of two condensers i 8, l.hese two conolensers are bridged. icy resistances 9 end respectively. reietion to the thickness of the pointer the voltege of the battery 6 the ciistence hetween the contluctors 1 end 2 is so chosen that when the pointer 3 is in its miclclie oosition, the production of e, disruptive iischcrge will oniy just be evoicled. Whom however, the pointer 3 moves either towards the conductor 1 or towards the concluctor 2, clisruptive discharge to the nearest conductor will he produced at once and,

eccortiing to the circninstonces, the con- (lensers 7 cool 8 wiil he chergeii. This chei'ge greclueily hows ewey vie the resistance 9 or 10 The connecting point of the condensers 7 end 8 is connected not only with one of the terniineis the hettery at but also with the negative terminal. of e. hissing hetterv 11 which applies the required]. bios to the grids 12 end 13 of two triocles V and V The enocles it and 15 of these trioiies are connecteci vie the primary windings 19 end 20 respectiveiy out two tronsz fcrrners with the positive terniinei ct enocle hottery 521. The two trioties "further comprise inconclescent cethocles 16 cool it respectively which ere both suppiieci by e hettery i Now the errengement is such thet when the pointer 3 occupies its iniclclloposition and the condensers? and 8 ore olischergedi, the

tubes V "V ere trsversetl by e smelt precticeiiy negiigihie enocie current. It, however the pointer 13 is rnovecl out of its rniiiliieposi" on, s, disruptive clischerge will he produce-ti one of the two grids i2 encl i3 acquires positive charge so that either in the it) or in the winding 2'!) clicectcurrent excitation teltes place.

The trenstorroer with the winch 1'9 valso cor e second winding 22 which included the supply circuit of the eiectric 5 which hosted by o current in sclcii" tion thi 24: which supgoiieol by hettery 25 t losing shout pernionent rnegnetizetion oi the trensforrnen This msgnetizetion is con trerjy to that prociuced by the winding 19 when the istter is traversed lay on enocle current. The result thereof is thet the inductive reectence oi the winolin 22 increases es soon es the winding 19 is enciteo,

The other trsnstormer which pertains the winding 26 comprises at seconolery windiing; 23 which is eiso loceteol in the supniy circuit oi the tumece 5 end in series with the winding 22 As iong es no current posses through the winding 20 the everege megnetic induction in the core of this trenstormer is almost equel to zero end the inductive re 1 which consequently rosy till 'iiii actance of the coil 23 has a maximum value. As soon as the winding 20 is excited, the inductive reactance on the coil 23 decreases.

From the foregoing it consequently follows that when the grid 12 becomes positive, the inductive reactance of the winding 22 increases while the inductive reactance of the winding 23 remains-the same. The intensity of the current circulating in the supply circuit of the furnace 5 and therefore the temperature of the latter will consequently decrease. If consequently the arrangement is made such that when the temperature of the furnace increases the needle 3 moves towards the conductor 1 and vice versa, it is possible in'the manner above described to keep the temperature of the furnace constant within narrow limits.

As will be obvious from the foregoing, the winding 22 normally has a low self-induction, while the winding 23 normally has a relatively high self-induction. If the temperature of the furnace becomes too great, the supply thereto must be decreased, and this result is accomplished by increasing the induction of the winding 23. If on the other hand, the temperature decreases, the supplyv current must be increased, and this result is accomplished by decreasing the inductance of the winding 23.

The winding 24 is mounted about the same core as the winding 22, and because of its self-inductance, employs a certain quantum of the magnetizing flux flowing through the core, so that the self-induction of the winding 22 is appreciably decreased because of lack of magnetizing flux. Now, if the current supply increases, raising the temperature in the furnace 5, contacts are completed I through the tube V whereby a circuit is completed through the winding 19 wound on the same core as the windings 22 and 24 but in opposite sense to the winding 24. Thus the magnetization efiects of the two windings 19 and 24 on the same core have the tendency to neutralize each other, whereby the full magnetization flux of the core is available to produce self-induction in the winding 22, thereby decreasing the current flow.

On the other hand, should the temperature in the furnace 5 fall below a certain point, a circuit is completed through the valve V and winding 20 whereby a portion of the magnetic flux in the core on which the winding 23 is wound is withdrawn to produce selfinductionof the winding 20, whereby the effective self-induction of the winding 23 is diminished, and the current flow through the supply current is correspondingly increased.

Although the arrangement as above described is only used for keeping constant the temperature of a body heated by alternating current, it is obvious that many other, quite difi'erent applications are possible. In fact it is nearly always possible to bring about the displacements of a movable conductor such,

for example as a pointer, by the action of the tion, it will always be'possible to cause these anode circuits to influence the magnitude to be controlled in such manner that they exert an opposite influence thereon.

What I claim is 1. A temperature regulator, comprisin a movable conductor, stationary conductors v etween which the movable conductor is located, the instantaneous position of the said movable conductor'being controlled by the temperature to be regulated, thermionic valves cooperating with the said stationary conductors, input circuits for the said valves, each of the stationary conductors forming a contact in the corresponding input circuit, a plate circuit for each of the said valves, an inductive winding in the plate circuit of each valve, a core for each of the said windings, a body to be heated, a supply circuit for the said body,

and a further winding on each of the said cores, the said last-mentioned windings lying in the said supply circuit, means supplying a flux to one of the said cores in opposite sense to that supplied by the'corresponding last mentioned winding.

2. A temperature regulator, comprising a movable conductor, stationary conductors between which the movable conductor is placed, the instantaneous position of the said movable conductor being controlled by the temperature to be regulated, the stationary conductors being arranged at some distance apart, two thermionic valves having control grids, cathodes and plates, two reslstance-shunted condensers, one cooperating with each of the thermionic valves, the said stationary conductors each. being connected to the control grid of the corresponding valve and to one of the electrodes of the corresponding condenser, a source of potential to which the said movable conductor is connected, the other electrodes of each of the condensers being connected to the other side of the said potential source and to the cathode of the said valves,

each other, and means supplying a ux to one oi the said cores in opposite sense to that supplied by the corresponding last-mentioned winding,

3. A temperature regulator, comprising) a movable conductor, stationary conductors tween which the movable conductor is laced,

the instantaneous position of the sai movable conductor being controlled by the temperature to he regulatedi the stationary conductors being arrange at some distance apart, two thermionic valves having control grids, cathodes and plates, two resistanceing condenser, a source of potential to which the said movable conductor is connected, the other electrodes of each of the condensers being connected to the other side of the said potential source and to the cathodes of the said valves, a plate circuit for each of the valves, an inductive winding in the plate circult of each of the valves, and carrying the plate current thereof, a separate core for each of the said windings, each winding being connected in the (plate circuit of the corresponding valve an a winding in the said su ply circuit on each of the said cores, each 0 the first-mentioned windings being adapted to vary the magnetization of the corresponding core in senses opposite to .each other, an auxiliary winding on one of the said cores wound in a direction opposite to that of the corresponding platecircuit winding, and a direct current ma netization source for the said auxiliary winding, whereby the effects of the'two windings on the core neutralize eachother and permit increase of the reactance of the corresponding supply circuit winding.

In testimony whereof I have signed my name to this specification. POPKO RElNDER DIJKSTERHUIS.

carrying the plate current, a supply circuit carrying the heating current, 

